/*
 *  ircd-ratbox: A slightly useful ircd.
 *  ircd.c: Starts up and runs the ircd.
 *
 *  Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
 *  Copyright (C) 1996-2002 Hybrid Development Team
 *  Copyright (C) 2002-2005 ircd-ratbox development team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
 *  USA
 *
 *  $Id: ircd.c 26128 2008-10-03 18:07:46Z androsyn $
 */

#include "ratbox_lib.h"
#include "setup.h"
#include "config.h"
#include "stdinc.h"
#include "struct.h"
#include "ircd.h"
#include "channel.h"
#include "class.h"
#include "client.h"
#include "hash.h"
#include "match.h"
#include "ircd_signal.h"
#include "hostmask.h"
#include "numeric.h"
#include "parse.h"
#include "restart.h"
#include "s_auth.h"
#include "s_conf.h"
#include "s_log.h"
#include "s_serv.h"		/* try_connections */
#include "s_stats.h"
#include "scache.h"
#include "send.h"
#include "whowas.h"
#include "hook.h"
#include "modules.h"
#include "ircd_getopt.h"
#include "newconf.h"
#include "reject.h"
#include "s_conf.h"
#include "s_newconf.h"
#include "cache.h"
#include "monitor.h"
#include "dns.h"
#include "bandbi.h"
#include "sslproc.h"
#include "supported.h"
/*
 * Try and find the correct name to use with getrlimit() for setting the max.
 * number of files allowed to be open by this process.
 */

/* /quote set variables */
struct SetOptions GlobalSetOptions;

/* configuration set from ircd.conf */
struct config_file_entry ConfigFileEntry;
/* server info set from ircd.conf */
struct server_info ServerInfo;
/* admin info set from ircd.conf */
struct admin_info AdminInfo;

struct Counter Count;
struct ServerStatistics ServerStats;

int maxconnections;
struct Client me;		/* That's me */
struct LocalUser meLocalUser;	/* That's also part of me */

rb_dlink_list global_client_list;

/* unknown/client pointer lists */
rb_dlink_list unknown_list;	/* unknown clients ON this server only */
rb_dlink_list lclient_list;	/* local clients only ON this server */
rb_dlink_list serv_list;	/* local servers to this server ONLY */
rb_dlink_list global_serv_list;	/* global servers on the network */
rb_dlink_list oper_list;	/* our opers, duplicated in lclient_list */

static unsigned long initialVMTop = 0;	/* top of virtual memory at init */
const char *logFileName = LPATH;
const char *pidFileName = PPATH;

char **myargv;
int dorehash = 0;
int dorehashbans = 0;
int doremotd = 0;
int kline_queued = 0;
int server_state_foreground = 0;
int printVersion = 0;
int ircd_ssl_ok = 0;
int zlib_ok = 1;

int testing_conf = 0;
int conf_parse_failure = 0;
time_t startup_time;

/* Set to zero because it should be initialized later using
 * initialize_server_capabs
 */
int default_server_capabs = CAP_MASK;

int splitmode;
int splitchecking;
int split_users;
int split_servers;
int eob_count;

void
ircd_shutdown(const char *reason)
{
	struct Client *target_p;
	rb_dlink_node *ptr;

	RB_DLINK_FOREACH(ptr, lclient_list.head)
	{
		target_p = ptr->data;

		sendto_one(target_p, ":%s NOTICE %s :Server Terminating. %s",
			   me.name, target_p->name, reason);
	}

	RB_DLINK_FOREACH(ptr, serv_list.head)
	{
		target_p = ptr->data;

		sendto_one(target_p, ":%s ERROR :Terminated by %s", me.name, reason);
	}

	ilog(L_MAIN, "Server Terminating. %s", reason);
	close_logfiles();

	unlink(pidFileName);
	exit(0);
}

/*
 * get_vm_top - get the operating systems notion of the resident set size
 */
static unsigned long
get_vm_top(void)
{
	/*
	 * NOTE: sbrk is not part of the ANSI C library or the POSIX.1 standard
	 * however it seems that everyone defines it. Calling sbrk with a 0
	 * argument will return a pointer to the top of the process virtual
	 * memory without changing the process size, so this call should be
	 * reasonably safe (sbrk returns the new value for the top of memory).
	 * This code relies on the notion that the address returned will be an 
	 * offset from 0 (NULL), so the result of sbrk is cast to a size_t and 
	 * returned. We really shouldn't be using it here but...
	 */
#ifndef _WIN32
	void *vptr = sbrk(0);
	return (unsigned long)vptr;
#else
	return -1;
#endif
}

/*
 * get_maxrss - get the operating systems notion of the resident set size
 */
unsigned long
get_maxrss(void)
{
	return get_vm_top() - initialVMTop;
}

/*
 * print_startup - print startup information
 */
static void
print_startup(int pid)
{
	printf("ircd: version %s\n", ircd_version);
	printf("ircd: pid %d\n", pid);
#ifndef RATBOX_PROFILE
	printf("ircd: running in %s mode from %s\n",
	       !server_state_foreground ? "background" : "foreground", ConfigFileEntry.dpath);
#else
	printf("ircd: running in foreground mode from %s for profiling\n", ConfigFileEntry.dpath);
#endif
}

/*
 * init_sys
 *
 * inputs	- boot_daemon flag
 * output	- none
 * side effects	- if boot_daemon flag is not set, don't daemonize
 */
static void
init_sys(void)
{
#if defined(RLIMIT_NOFILE) && defined(HAVE_SYS_RESOURCE_H)
	struct rlimit limit;

	if(!getrlimit(RLIMIT_NOFILE, &limit))
	{
		maxconnections = limit.rlim_cur;
		if(maxconnections <= MAX_BUFFER)
		{
			fprintf(stderr, "ERROR: Shell FD limits are too low.\n");
			fprintf(stderr,
				"ERROR: ircd-ratbox reserves %d FDs, shell limits must be above this\n",
				MAX_BUFFER);
			exit(EXIT_FAILURE);
		}
		return;
	}
#endif /* RLIMIT_FD_MAX */
	maxconnections = MAXCONNECTIONS;
}

static int
make_daemon(void)
{
#ifndef _WIN32
	int pid, fd;

	if((pid = fork()) < 0)
	{
		perror("fork");
		exit(EXIT_FAILURE);
	}
	else if(pid > 0)
	{
		print_startup(pid);
		exit(EXIT_SUCCESS);
	}

	setsid();

	fd = open("/dev/null", O_RDWR);
	/* dup2 should close the target fd if its open */
	dup2(fd, 0);
	dup2(fd, 1);
	dup2(fd, 2);
	close(fd);
#endif
	return 0;
}

static const char *basedir = DPATH;
static const char *configfile = CPATH;

struct lgetopt myopts[] = {
	{"basedir", &basedir,
	 ISTRING, "Base directory to run ircd from"},
	{"configfile", &configfile,
	 ISTRING, "File to use for ircd.conf"},
	{"logfile", &logFileName,
	 ISTRING, "File to use for ircd.log"},
	{"pidfile", &pidFileName,
	 ISTRING, "File to use for process ID"},
	{"foreground", &server_state_foreground,
	 YESNO, "Run in foreground (don't detach)"},
	{"version", &printVersion,
	 YESNO, "Print version and exit"},
	{"conftest", &testing_conf,
	 YESNO, "Test the configuration files and exit"},
	{"help", NULL, USAGE, "Print this text"},
	{NULL, NULL, ISTRING, NULL},
};

static void
check_rehash(void *unusued)
{
	/*
	 * Check to see whether we have to rehash the configuration ..
	 */
	if(dorehash)
	{
		rehash(1);
		dorehash = 0;
	}

	if(dorehashbans)
	{
		rehash_bans(1);
		dorehashbans = 0;
	}

	if(doremotd)
	{
		sendto_realops_flags(UMODE_ALL, L_ALL,
				     "Got signal SIGUSR1, reloading ircd motd file");
		cache_user_motd();
		doremotd = 0;
	}
}

/*
 * initalialize_global_set_options
 *
 * inputs       - none
 * output       - none
 * side effects - This sets all global set options needed 
 */
static void
initialize_global_set_options(void)
{
	memset(&GlobalSetOptions, 0, sizeof(GlobalSetOptions));
	/* memset( &ConfigFileEntry, 0, sizeof(ConfigFileEntry)); */

	GlobalSetOptions.maxclients = ServerInfo.default_max_clients;

	if(GlobalSetOptions.maxclients > (maxconnections - MAX_BUFFER)
	   || (GlobalSetOptions.maxclients <= 0))
		GlobalSetOptions.maxclients = maxconnections - MAX_BUFFER;

	GlobalSetOptions.autoconn = 1;

	GlobalSetOptions.spam_time = MIN_JOIN_LEAVE_TIME;
	GlobalSetOptions.spam_num = MAX_JOIN_LEAVE_COUNT;

	if(ConfigFileEntry.default_floodcount)
		GlobalSetOptions.floodcount = ConfigFileEntry.default_floodcount;
	else
		GlobalSetOptions.floodcount = 10;

	split_servers = ConfigChannel.default_split_server_count;
	split_users = ConfigChannel.default_split_user_count;

	if(split_users && split_servers
	   && (ConfigChannel.no_create_on_split || ConfigChannel.no_join_on_split))
	{
		splitmode = 1;
		splitchecking = 1;
	}

	GlobalSetOptions.ident_timeout = IDENT_TIMEOUT;

	rb_strlcpy(GlobalSetOptions.operstring,
		   ConfigFileEntry.default_operstring, sizeof(GlobalSetOptions.operstring));
	rb_strlcpy(GlobalSetOptions.adminstring,
		   ConfigFileEntry.default_adminstring, sizeof(GlobalSetOptions.adminstring));

	/* memset( &ConfigChannel, 0, sizeof(ConfigChannel)); */

	/* End of global set options */

}

/*
 * initialize_server_capabs
 *
 * inputs       - none
 * output       - none
 */
static void
initialize_server_capabs(void)
{
	default_server_capabs &= ~CAP_ZIP;
}


/*
 * write_pidfile
 *
 * inputs       - filename+path of pid file
 * output       - none
 * side effects - write the pid of the ircd to filename
 */
static void
write_pidfile(const char *filename)
{
	FILE *fb;
	char buff[32];
	if((fb = fopen(filename, "w")))
	{
		unsigned int pid = (unsigned int)getpid();

		rb_snprintf(buff, sizeof(buff), "%u\n", pid);
		if((fputs(buff, fb) == -1))
		{
			ilog(L_MAIN, "Error writing %u to pid file %s (%s)",
			     pid, filename, strerror(errno));
		}
		fclose(fb);
		return;
	}
	else
	{
		ilog(L_MAIN, "Error opening pid file %s", filename);
	}
}

/*
 * check_pidfile
 *
 * inputs       - filename+path of pid file
 * output       - none
 * side effects - reads pid from pidfile and checks if ircd is in process
 *                list. if it is, gracefully exits
 * -kre
 */
static void
check_pidfile(const char *filename)
{
	FILE *fb;
	char buff[32];
	pid_t pidfromfile;

	/* Don't do logging here, since we don't have log() initialised */
	if((fb = fopen(filename, "r")))
	{
		if(fgets(buff, 20, fb) != NULL)
		{
			pidfromfile = atoi(buff);
			if(!rb_kill(pidfromfile, 0))
			{
				printf("ircd: daemon is already running\n");
				exit(-1);
			}
		}
		fclose(fb);
	}
}

/*
 * setup_corefile
 *
 * inputs       - nothing
 * output       - nothing
 * side effects - setups corefile to system limits.
 * -kre
 */
static void
setup_corefile(void)
{
#ifdef HAVE_SYS_RESOURCE_H
	struct rlimit rlim;	/* resource limits */

	/* Set corefilesize to maximum */
	if(!getrlimit(RLIMIT_CORE, &rlim))
	{
		rlim.rlim_cur = rlim.rlim_max;
		setrlimit(RLIMIT_CORE, &rlim);
	}
#endif
}

static void
ilogcb(const char *buf)
{
	ilog(L_MAIN, "libratbox reports: %s", buf);
}

static void
restartcb(const char *buf)
{
	ilog(L_MAIN, "libratbox has called the restart callback: %s", buf);
	restart(buf);
}

static void
diecb(const char *buf)
{
	if(buf != NULL)
		ilog(L_MAIN, "libratbox has called the die callback..aborting: %s", buf);
	else
		ilog(L_MAIN, "libratbox has called the die callback..aborting");
	abort();
}

#ifndef _WIN32
static int
seed_with_urandom(void)
{
	unsigned int seed;
	int fd;

	fd = open("/dev/urandom", O_RDONLY);
	if(fd >= 0)
	{
		if(read(fd, &seed, sizeof(seed)) == sizeof(seed))
		{
			close(fd);
			srand(seed);
			return 1;
		}
	}
	return 0;
}
#endif

static void
seed_with_clock(void)
{
	const struct timeval *tv;
	rb_set_time();
	tv = rb_current_time_tv();
	srand(tv->tv_sec ^ (tv->tv_usec | (getpid() << 20)));
}

static void
seed_random(void *unused)
{
	unsigned int seed;
	if(rb_get_random(&seed, sizeof(seed)) == -1)
	{
#ifndef _WIN32
		if(!seed_with_urandom())
#endif
			seed_with_clock();
		return;
	}
	srand(seed);
}

int
ratbox_main(int argc, char *argv[])
{
	char emptyname[] = "";
	int r;
	/* Check to see if the user is running us as root, which is a nono */
#ifndef _WIN32
	if(geteuid() == 0)
	{
		fprintf(stderr, "Don't run ircd as root!!!\n");
		exit(EXIT_FAILURE);
	}
#endif
	init_sys();



	myargv = argv;
	parseargs(&argc, &argv, myopts);

	if(printVersion)
	{
		printf("ircd: version %s\n", ircd_version);
		printf("ircd: configure options\n");
		puts(RATBOX_CONFIGURE_OPTS);
		exit(EXIT_SUCCESS);
	}

	if(chdir(basedir))
	{
		fprintf(stderr, "Unable to chdir to %s: %s\n", basedir, strerror(errno));
		exit(EXIT_FAILURE);
	}

	add_all_conf_settings();

	r = read_config_file(configfile);
	if(r > 0)
	{
		fprintf(stderr,
			"ERROR: Unable to start ircd: found %d syntax error(s) whlist loading config file.  Try running with -conftest\n",
			r);
		return 1;
	}

	if(testing_conf)
		fprintf(stderr, "Syntax OK, doing second pass...\n");


	r = check_valid_entries();
	if(r > 0)
	{
		fprintf(stderr,
			"ERROR: Unable to start ircd: found %d error(s) whilst loading config file.  Try running with -conftest\n",
			r);
		return 1;
	}

	if(testing_conf)
		fprintf(stderr, "Second pass reports OK\n");

	ConfigFileEntry.dpath = basedir;
	ConfigFileEntry.configfile = configfile;	/* Server configuration file */

	/* Check if there is pidfile and daemon already running */
	if(!testing_conf)
	{
		check_pidfile(pidFileName);

		if(!server_state_foreground)
			make_daemon();
		else
			print_startup(getpid());
	}

	/* This must be after we daemonize.. */
	rb_lib_init(ilogcb, restartcb, diecb, 1, maxconnections, DNODE_HEAP_SIZE, FD_HEAP_SIZE);
	rb_linebuf_init(LINEBUF_HEAP_SIZE);

	set_default_conf();
	rb_set_time();
	setup_corefile();
	initialVMTop = get_vm_top();

	memset(&me, 0, sizeof(me));
	me.name = emptyname;
	memset(&meLocalUser, 0, sizeof(meLocalUser));
	me.localClient = &meLocalUser;

	/* Make sure all lists are zeroed */
	memset(&unknown_list, 0, sizeof(unknown_list));
	memset(&lclient_list, 0, sizeof(lclient_list));
	memset(&serv_list, 0, sizeof(serv_list));
	memset(&global_serv_list, 0, sizeof(global_serv_list));
	memset(&oper_list, 0, sizeof(oper_list));

	rb_dlinkAddTail(&me, &me.node, &global_client_list);

	memset(&Count, 0, sizeof(Count));
	memset(&ServerInfo, 0, sizeof(ServerInfo));
	memset(&AdminInfo, 0, sizeof(AdminInfo));
	memset(&ServerStats, 0, sizeof(struct ServerStatistics));


	/* Initialise the channel capability usage counts... */
	init_chcap_usage_counts();

	ConfigFileEntry.connect_timeout = 30;	/* Default to 30 */

	umask(077);		/* better safe than sorry --SRB */


	setup_signals();
	init_s_conf();
	init_s_newconf();



#if defined(__CYGWIN__) || defined(_WIN32) || defined(RATBOX_PROFILE)
	server_state_foreground = 1;
#endif

	if(ConfigServerHide.links_delay > 0)
		rb_event_add("cache_links", cache_links, NULL, ConfigServerHide.links_delay);
	else
		ConfigServerHide.links_disabled = 1;

	if(ConfigFileEntry.use_egd && (ConfigFileEntry.egdpool_path != NULL))
	{
		rb_init_prng(ConfigFileEntry.egdpool_path, RB_PRNG_EGD);
	}
	else
		rb_init_prng(NULL, RB_PRNG_DEFAULT);
	seed_random(NULL);

	init_main_logfile(logFileName);
	init_hash();
	init_host_hash();
	clear_hash_parse();
	init_client();
	init_channels();
	initclass();
	initwhowas();
	init_hook();
	init_reject();
	init_cache();
	init_monitor();
	init_isupport();
#ifdef STATIC_MODULES
	load_static_modules();
#else
	load_all_modules(1);
	load_core_modules(1);
#endif
	init_resolver();	/* Needs to be setup before the io loop */
	init_bandb();
	init_ssld();

	load_conf_settings();

	rehash_bans(0);

#ifndef STATIC_MODULES
	mod_add_path(MODULE_DIR);
	mod_add_path(MODULE_DIR "/autoload");
#endif

	initialize_server_capabs();	/* Set up default_server_capabs */
	initialize_global_set_options();

	init_auth();		/* Initialise the auth code - depends on global set options */
	rehash_dns_vhost();	/* load any vhost dns binds now */

	if(ServerInfo.name == NULL)
	{
		fprintf(stderr, "ERROR: No server name specified in serverinfo block.\n");
		ilog(L_MAIN, "No server name specified in serverinfo block.");
		exit(EXIT_FAILURE);
	}
	me.name = ServerInfo.name;

	if(ServerInfo.sid[0] == '\0')
	{
		fprintf(stderr, "ERROR: No server sid specified in serverinfo block.\n");
		ilog(L_MAIN, "No server sid specified in serverinfo block.");
		exit(EXIT_FAILURE);
	}
	strcpy(me.id, ServerInfo.sid);
	init_uid();

	/* serverinfo{} description must exist.  If not, error out. */
	if(ServerInfo.description == NULL)
	{
		fprintf(stderr, "ERROR: No server description specified in serverinfo block.\n");
		ilog(L_MAIN, "ERROR: No server description specified in serverinfo block.");
		exit(EXIT_FAILURE);
	}
	rb_strlcpy(me.info, ServerInfo.description, sizeof(me.info));

	if(ServerInfo.ssl_cert != NULL && ServerInfo.ssl_private_key != NULL)
	{
		/* just do the rb_setup_ssl_server to validate the config */
		if(!rb_setup_ssl_server
		   (ServerInfo.ssl_cert, ServerInfo.ssl_private_key, ServerInfo.ssl_dh_params))
		{
			ilog(L_MAIN, "WARNING: Unable to setup SSL.");
			ircd_ssl_ok = 0;
		}
		else
			ircd_ssl_ok = 1;
	}

	if(testing_conf)
	{
		exit(conf_parse_failure ? 1 : 0);
	}

	me.from = &me;
	me.servptr = &me;
	SetMe(&me);
	make_server(&me);
	startup_time = rb_current_time();
	add_to_hash(HASH_CLIENT, me.name, &me);
	add_to_hash(HASH_ID, me.id, &me);

	rb_dlinkAddAlloc(&me, &global_serv_list);

	check_class();
	write_pidfile(pidFileName);
	load_help();
	open_logfiles(logFileName);

	ilog(L_MAIN, "Server Ready");

	/* We want try_connections to be called as soon as possible now! -- adrian */
	/* No, 'cause after a restart it would cause all sorts of nick collides */
	/* um.  by waiting even longer, that just means we have even *more*
	 * nick collisions.  what a stupid idea. set an event for the IO loop --fl
	 */
	rb_event_addish("try_connections", try_connections, NULL, STARTUP_CONNECTIONS_TIME);
	rb_event_addonce("try_connections_startup", try_connections, NULL, 2);
	rb_event_add("check_rehash", check_rehash, NULL, 3);
	rb_event_addish("reseed_srand", seed_random, NULL, 300);	/* reseed every 10 minutes */

	if(splitmode)
		rb_event_add("check_splitmode", check_splitmode, NULL, 5);

	rb_lib_loop(0);		/* we'll never return from here */
	return 0;
}
